In the beginning, Ricardo Montalban, who plays Louis Montoya, is watching what is supposed to be an old clip of himself as a young matador. The clip he is watching is actually from the movie Santa (1943), in which Montalban plays a bullfighter.
Columbo must give a Mexican police officer his I.D. following a car accident. Columbo's signature can briefly be seen in close-up, clearly showing his full name to be "Lt. Frank Columbo". This is the second episode in which "Frank" can be seen on the I.D., the first being Dead Weight (1971).
One of two episodes where a murder is committed using animals. Here the victim died after bull attack; in How to Dial a Murder (1978), the victim died after the attack of 2 Dobermans, Laurel & Hardy.
One of the rare instances where Columbo discusses a previous case, which in this case was Troubled Waters (1975).
Columbo talks about Troubled Waters (1975) with the local police chief in Mexico, referring to it modestly as the time he got seasick. Columbo learns that the case has made him a hero in Mexico, where all of the newspapers reported how he solved the murder at sea. Columbo's fame from that case is probably what saves him from getting his car permanently confiscated after his traffic accident.